Tightness Tests of Lamination-Bonded Electric Sheet Stacks

The article presents the results of tightness tests involving specimens of lamination-bonded electric sheet stacks exposed to water pressure restricted within the range of 2 bars to 14 bars. Cylindrical specimens were made of NO27 SURALAC 9000 electric sheets with adhesive, some of which were directly exposed to a pressure test after stacking, whereas some were additionally impregnated with resin prior to testing. The test results indicated that the specimens additionally impregnated with resin did not reveal any signs of leakage when exposed to a water pressure of up to 10 bar for 10 minutes. During the tests, the pressure in the measurement system remained constant throughout the entire 10-minute period (no pressure drop in the measurement system was observed).